The road is among the worst 10 per cent, posing an 'unacceptably high risk' to drivers and motorcyclists the Road Safety Foundation has said.
However, the study by the road safety charity found that safety on three other A roads in Berwickshire improved between 2006 and 2008, compared to 2005 to 2007.
The annual study shows the statistical risk of death or serious injury occuring on the country's motorways and A roads, calculating the risk by comparing the frequency of death and serious injury on every stretch of road with how much traffic each road carries.
The latest study results, covering 2006 to 2008, showed that the A6105 between Berwick and Duns and Duns to Earlston was reduced to a 'medium risk' road from 'medium to high risk.'
It also revealed that safety on the A697 from Coldstream to Carfraemill improved, with it now classed as a 'low to medium risk' road, and on the A1107 coastal road from Burnmouth to Cockburnspath, with it becoming a 'low risk' road.
But, the A6112 has gone the other way, with it being re-classified from 'medium risk' to 'medium to high,' the second worst rating, making it one of just 10 per cent of all the A roads and motorways in the UK to be rated in the worst two categories.
Two roads in the Scottish Borders have been given the worst rating of 'high risk,' the A6088 from Hawick to the Carter Bar, and the A708 from Selkirk to Moffat.
The A1, both north and south of the border, from the Edinburgh city bypass to Alnwick has remained rated at 'low to medium risk.'
The survey covers a total of 28,000 miles of the UK's road network, with Scotland having the highest average risk rating of all the regions.
Commenting on the report's findings, Dr Joanne Hill, director of the Road Safety Foundation said: "As the road budget becomes tighter, emphasis must be on saving lives with less. It means systematic attention to detail, prioritising treatment of the highest risk routes most likely to benefit from low-cost, high-return countermeasures.
"This year's report shows that not only can Britain reduce roads deaths and serious injuries but that, by targeting a relatively small mileage of high risk roads, we can do so with good economic returns. Too often we pay for emergency services, hospitals and care for the disabled rather than taking easy steps to put road design faults right.
"There are practical examples of how, with attention to detail, some authorities are slashing the toll of death and serious injury on high risk stretches by as much as three-quarters.
"Simple, relatively inexpensive engineering measures, such as improvements to signing and lining, resurfacing and the layout of signals at junctions, are paying dividends and are affordable particularly when done as part of well planned routine maintenance."